DIN ISO 21748:2014-05

Knowledge of the uncertainty associated with measurement results is essential to the interpretation of the results. Without quantitative assessments of uncertainty, it is impossible to decide whether observed differences between results reflect more than experimental variability, whether test items comply with specifications, or whether laws based on limits have been broken. Without information on uncertainty, there is a risk of misinterpretation of results. Incorrect decisions taken on such a basis can result in unnecessary expenditure in industry, incorrect prosecution in law, or adverse health or social consequences. This standard gives guidance for evaluation of measurement uncertainties using data obtained from studies conducted in accordance with ISO 5725-2:1994, and for comparison of collaborative study results with measurement uncertainty (MU) obtained using formal principles of uncertainty propagation. This standard is applicable in all measurement and test fields where an uncertainty associated with a result has to be determined. This standard does not describe the application of repeatability data in the absence of reproducibility data. This standard assumes that recognized, non-negligible systematic effects are corrected, either by applying a numerical correction as part of the method of measurement, or by investigation and removal of the cause of the effect. The recommendations in this standard are primarily for guidance. It is recognized that while the recommendations presented do form a valid approach to the evaluation of uncertainty for many purposes, it is also possible to adopt other suitable approaches. Regarding the German collaboration and this translation of ISO 21478:2010, Working Committee NA 147-00-02 AA "Angewandte Statistik" ("Applied statistics") at the Quality Management, Statistics and Certification Standards Committee (NQSZ) of DIN, the German Standardization Institute e. V., is responsible.